The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1967 - 1972 Chevrolet & GMC Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 08-25-2018, 10:45 PM   #1
Steven67c10
Registered User
 
Join Date: Jul 2018
Location: Spring, TX
Posts: 6
Over heating problem

Hey guys, so I just bought a 69 c10. Truck has a 350 with aluminum heads and cam. Truck has a/c as well. Well when cruising down the highway at about 65 it’s at 3200-3300 rpm. It starts to go up pretty quick. When I noticed it going to 220 I slowed down and pulled off the highway. I’ve noticed it only does it when I’m on the highway and staying at or above the 3k rpm range. At idle and just cruising around town it stays at 170-180 all the time.

Any help on what I need to do to fix this problem. It has dual fans but maybe I need a bigger radiator. Maybe a new thermostat sensor?

Thanks guys
Steven67c10 is offline   Reply With Quote
Old 08-25-2018, 11:53 PM   #2
Steeveedee
Who Changed This?
 
Steeveedee's Avatar
 
Join Date: Jan 2013
Location: Simi Valley, CA
Posts: 10,088
Re: Over heating problem

#1 cause for running hot at high speeds is a bad radiator. Getting it cleaned or replacing it should cure the problem.
__________________
~Steven

'70 Chevy 3/4T Longhorn CST 402/400/3.56 Custom Camper

Simi Valley, CA
Steeveedee is offline   Reply With Quote
Old 08-25-2018, 11:58 PM   #3
Boog
laying low
 
Boog's Avatar
 
Join Date: Mar 2001
Location: Searcy, Ark. USA
Posts: 12,957
Re: Over heating problem

Reducing the rpms will lower the engine heat as well. Either slow down or swap the rear end gears to a higher ratio will lower the engine heat. Or if ya got bucks, installing an over drive trans or gear vendors od unit will get ya there.
__________________
Boog
69 Chevy stepside, 358/T350, 4.11 posi, 4.5/4 drop, rallys, poboy driver
primer is finer
91 Chevy sportside, Tahoe, Yukon & GMC Crewcab All GM..'nuff said.

I stand for the flag and kneel at the cross
Boog is offline   Reply With Quote
Old 08-26-2018, 12:21 AM   #4
Jcfcamaro
Registered User
 
Jcfcamaro's Avatar
 
Join Date: Jul 2015
Location: Fairfax, Missouri
Posts: 1,054
Re: Over heating problem

I'd say it's the radiator also. Buy a new aluminum one as it will cool alot better. ECP makes a real nice one. That's Engineering cooling products. Put one in my Camaro and all my problems went away.
Jcfcamaro is offline   Reply With Quote
Old 08-26-2018, 01:30 PM   #5
68 P.O.S.
Registered User
 
Join Date: Jan 2007
Location: Puyallup, WA
Posts: 1,661
Re: Over heating problem

Do you have a shroud?
__________________
72 C10 lwb fleetside -stock 350/350 combo
68 P.O.S. is offline   Reply With Quote
Old 08-26-2018, 01:44 PM   #6
Jcfcamaro
Registered User
 
Jcfcamaro's Avatar
 
Join Date: Jul 2015
Location: Fairfax, Missouri
Posts: 1,054
Re: Over heating problem

Yes, My original radiator was taken to a shop and was redone. Had a shroud on it also, but would run hot. Everyone said to ditch the solid 4 blade fan and get a clutch fan so I did with no response.Even played around with different thermostats. Ended up buying the ECP radiator and all my problems went away. When I get closer to getting my 72 k10 with A/C I'm buying one for it. I have a factory radiator for it, but it would need sent to the shop to be tested/fixed and I'm not going down that path again and waste money.
Jcfcamaro is offline   Reply With Quote
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 03:37 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com